What is dllspec(dllimport) and dllspec(dllexport) means

Question

After googling, i came to know that Dllimport makes the function available for other modules,

is it mandatory to declare function with extern \"c\" identifier?

A

Answer 1

It also means that entries (in the form of static import and export tables) are created (by the linker) in the exe, dll..files, which document the dependencies between a provider and a consumer.